This invention relates to a plug for plugging the open end of a pipe; and in particular, a friction plug for plugging the outflow end of a high pressure pipe such as, for example, an oil well-head casing, a gas pipe or a high pressure water well casing.
Long sections of pipe are commonly used to access pockets of crude oil, natural gas, water or the like deep within the earth. Extensive drilling and the installation of sections of piping or casing are required to reach down into the earth and tap into a pocket of oil, for example. This process of drilling and adding pipe for casing is labor intensive and expensive. Many hundreds, or often thousands of feet of pipe or casing are required in the process.
Oil, for example, being deep in the earth, flows back up through the casing with tremendous force. The entire system of casing, well-head and rigging is under high pressure. Therefore, if the integrity of the casing is damaged by disassembly, rupture, or fire, it is quite difficult to repair or plug the high pressure casing or pipe. In most cases the casing is simply plugged by pouring a sealant, known in the industry as "mud", into the outflow end of the casing. The "mud" packs and forms an impervious plug inside the casing. This is an unsatisfactory solution to the problem since this plugging with "mud" renders the pipe useless. If there is an adequate reserve of oil, for example, in the pocket, the existing access pipe must be abandoned and a new access pipe drilled and new casing or pipe installed next to the plugged casing or pipe. This procedure is performed at considerable expense. The present invention, both recognizing and resolving these problems associated with plugging a high pressure pipe provides a unique and novel system for both plugging the pipe, yet allowing continued use of the existing pipe to access fluid or gas, thereby saving time, energy and the associated cost with permanently plugging an existing high pressure pipe, drilling a new access, and installing a new pipe or casing next to the plugged pipe.